I am going to guess A, since I think it is the pea aphid which has been fully sequenced. D seems quite possible too since I think that is the green peach aphid and there is a great deal of genetic and genomic work on that as well. I’ll stick with A as my guess though.

Oh right, the second question further supports my guess for A because it has been shown that the gene in the pea aphid for carotenoid production is thought to have come by horizontal gene transfer from a fungus.

I am going to pick image D only because it matches a post from 11/26/12 with the same DNA sequence with the same pea aphid photo. My guess is totally uneducated and based only on what I have read from other posts.

I have such a Ph. D. and can’t answer it without some research on the internet, Scott. But probably any whiz-kid undergrad biology student could, especially one with an interst in molecular evolution anad such.

The DNA part is just a plug and chug. The tricky part, and the part that took this week’s guessers the longest time to solve, is the old-fashioned ability to recognize what a species looks like from a picture. That they don’t teach anymore, alas.